What Causes Blister Like Bump On The Hip?

Hi, i have 4 blister like pimples in various area one in particular on my hip. i awoke thursday with them...the one on my hip i thought could have possibly b a spider bite so i went to doctor...he said it prob wasnt a spider bite but most likely an infected oil gland. i am 38 weeks pregnant and it has progressivly worsened. i do not know what to put on it to help it heal or to relieve the pain and pressure. Doc gave me some anti-biotics and doesnt seems to be helping